Xventilating w wheel or fan



(No Model.) 2 Sfi eet$Sheet 2.

W. H. A. DAVIDSON. VENTILATING WHEEL 0 FAN.

No. 598,216 Patented Feb. 1,1898.

' 1 mn'uulllullll mlmlllunin? FIE-m Nrrnrans I WILLIAM H. A. DAVIDSON,OF CAMBRIDGE, MASSACHUSETTS.

VENTILATiNG WHEEL OR FAN.

SPECIFICATION forming part of Letters Ilatent No. 598,216, datedFebruary 1, 1898.

Application filed July 1, 1895. Serial No. 554,624. (No model.) i

To all whom it may concern.-

Be it known that 1, WILLIAM H. A. DAVID- SON, a citizen of the UnitedStates, and a resi- I-Ieretofore ventilating wheels or fans have beenconstructed with blades of divers shapes set radially and at an angle toand across the axis of the shaft which constituted their cen 'ter ofrotation. In such fans only the forward or cutting edge of the blade waseffective to gather in the air, while the configuration of theblade-surface tended to disperse the volume of air passed through thefan in directions at various angles to the axis of rotation of the fan,and where the air was to be forced through ducts or confined channelsplaced in the rear of the fan such diverging currents tended to createfriction and resistance to the effective work of the fan.

I have in practical tests of my invention segment of a prolate spheroidwhen arranged in the fan as last above stated are better and moreefficiently adapted to concentrate and deliver the current of airthrough the fan in right lines, or nearly so, parallel with the axis ofthe fan, and with a minimum of frictional resistance where the air is tobe forced through ducts.

I have secured the best results by constructing the blade in the form ofa segment of a prolate spheroid or in the form of a spoonbowl, fromwhich its extreme ends have been cut oif in such manner as to provide ablade with an inner concave face and an outer convex face and byarranging such blades in the wheel or fan in manner following: I firstsocure upon the shaft or hub spokes, each of which projects from saidshaft with its longitudinal axis at the point of junction with the shaftor hub, eccentric to the axis of the latter; Upon each said spoke Isecure, preferably adj ustably, an arm which projects from the rear sideof said spoke with reference to the direction of rotation. Upon saidrearward-projecting arms I secure blades of the character abovedescribed, with their surfaces at approximately right angles tothelongitudinal axis of said spokes and angularly inclined to the verticalplane of the axis of rotation. Said blades are arranged to extendforward of the spokes and are set with their cutting edges nearest theperiphery of the wheel and their delivery edges nearest the center ofthe wheel.

The fan is mounted in a frame or bearings and driven in the ordinaryway. It may be used in connection with an air-duct or not,

as may be desired.

Within considerable limits the outline of the edges of the blade may bevaried, (I have shown two variations,) provided the essentialcurvatures, such as are found in a spoon-bowl,

are retained.

In the accompanying drawings, illustrating myinvention, Figure 1 is afront elevation of a fan embodying my invention. Fig. 2 is a sideelevation of the same. Fig. 3 is a rear View of the same,looking in thedirection of the arrows from line 00 w of Fig. 2.. Figs. 4E and 9 showthe mode of attaching and securing the blade, a portion of the bladebeing broken away and the arm and clamping-nut being shown in section.Fig. 5 shows a plan, a side, and a sectional view of the splitclamping-nut. Figs. 6, 7, and S are respectively front, side, and rearviews, differing from Figs. 1, 2, and 3 only in the shape of the outeredge of the blades. Fig. 10 is a section on line 2 z of Fig. 9.

Similar letters of reference indicate like parts where they occur in thedrawings.

A represents the blade, which may, as shown in Figs. 1, 2, 3, and 4,have the spoon-shaped outline, or, as shown in Figs. 6, 7, 8, and 9,while still preserving the curvatures of a spoon-bowl, may at the sametime have its opposite sides or edges more nearly parallel, and ineither case is provided with a stem or shank or secured upon an arm a,the lower end of which is threaded and adapted to be engaged by aninternally-threaded split clamp-nut n, provided with rectangular taperedsides adapted to fit into the correspondingly-tapered rectangularorifice in the spoke b and to be drawn thereinto bindingly by the actionof the check-nut against the under side of said spoke b, to rigidlysecure the blade in position with its surfaces at approximatelyforty-five degrees to and at the longitudinal axis of the arm andangularly inclined to the vertical plane of the axis of the fan. Thespokes b are located upon the side of the hub or shaft of a wheel or faneccentrically to the axis of the same and extend outward in a radialdirection from said hub or shaft. The spokes b may, if desired, form anintegral part of the hub or shaft.

. The shaft 3 may be mounted on bearings or in a frame in the usual wayand operated in the ordinary manner. The blade may be adj usted at anydesired angle to the axis of the shaft and thereby adapted to varyingconditions and exigencies of work.

I claim as my invention and desire to secure by Letters Patent- 1. Thecombination with the fan-shaft of spokes projecting therefrom,substantially spoon-shaped. blades secured to arms projecting from therear side of said spokes with reference to the direction of rotation,with their surfaces at approximately right angles to the longitudinalaxis of the spokes and inclined to the vertical plane of the axis ofrotation, the said blades extending forward of the spokes and so setthat their cutting edges are nearest the periphery and their deliveryedges nearest the center of the wheel.

2. In a ventilating wheel or fan spokes located on the side of the shaftof rotation and projecting in a radial direction therefrom with thelongitudinal axis of said spokes at their junction with said shafteccentric to the axis of the latter, arms adjustably secured upon saidspokes and projecting from the rear side thereof with reference to thedirection of rotation, and substantially spoon-shaped blades secured tosaid arms and extending forward of said spokes with their surfaces atapproximately right angles to the longitudinal axis of said spokes andangularly inclined to the vertical plane of the axis of rotation and soset that their cutting edges are nearest the periphery and theirdelivery edges nearest the center of the wheel.

3. In a ventilating wheel or fan spokes I) each located upon the side ofthe shaft of rotation and projecting in a radial direction therefromwith their longitudinal axis at the point of junction with said shafteccentric to the axis of the latter, combined with blades arranged uponthe rear side of said spokes with reference to the direction ofrotation,

with their surfaces at approximately right angles to the longitudinalaxis of said spokes and inclined to the vertical plane of the axis ofrotation, the said blades extending forward of the spokes and so setthat their cutting edges are nearest the periphery and their deliveryedgesnearest the center of the wheel.

4. The combination with a shaft and hub, of spokes b secured on the sideof said hub and projecting in a radial direction therefrom, with thelongitudinal axis of said spokes at the point of union with the hubeccentric to the axis of the latter, and blades A adj ustably securedand centrally supported upon the rear side of said spokes with referenceto the direction of rotation with their surfaces at approximately rightangles to the longitudinal axis of the spokes and inclined to thevertical plane of the axis of rotation, the said blades extendingforward of the spokes and so set that their cutting edges are nearestthe periphery and their delivery edges nearest the center of the wheel.

5. In a ventilating wheel or fan, the blades A provided with a threadedstem or shank, the annular split clamping-nut c and checknut n, allcombined with each other and with the spokes I) provided with arectangulartapered orifice, and arranged and adapted to serve asspecified.

In testimony whereof I have hereunto set my hand, in presence of twowitnesses, this 29th day of June, 1895.

WILLIAM H. A. DAVIDSON.

Witnesses:

HENRY MARSH, J11, E. A. GOLDING.

